Financial Instruments (Narrative) (Details) € in Millions |
9 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2018
USD ($)
|
Jun. 30, 2018
EUR (€)
|
Sep. 30, 2017
USD ($)
|
Sep. 30, 2017
EUR (€)
|
|
| Derivative [Line Items] | ||||
| Net liability position of derivatives with credit risk-related contingent features | $ 51,100,000 | $ 34,600,000 | ||
| Collateral posted on liability positions with credit risk-related contingent features | 0 | |||
| Collateral amount that counterparties would be required to post | $ 109,900,000 | 138,500,000 | ||
| Forward Exchange Contracts | Cash Flow Hedges | ||||
| Derivative [Line Items] | ||||
| Maximum remaining maturity of foreign currency derivatives | 1 year 9 months 18 days | 1 year 9 months 18 days | ||
| Foreign Currency Debt | Euro Denominated | ||||
| Derivative [Line Items] | ||||
| Notional amount included in designated foreign currency denominated debt | $ 1,063,300,000 | € 910.1 | $ 1,077,700,000 | € 912.2 |